Picture of flying drone

Award-winning sensor signal processing research at Strathclyde...

The Strathprints institutional repository is a digital archive of University of Strathclyde's Open Access research outputs. Strathprints provides access to thousands of Open Access research papers by University of Strathclyde researchers, including by Strathclyde researchers involved in award-winning research into technology for detecting drones. - but also other internationally significant research from within the Department of Electronic & Electrical Engineering.

Strathprints also exposes world leading research from the Faculties of Science, Engineering, Humanities & Social Sciences, and from the Strathclyde Business School.

Discover more...

The effect of intensity of excitation on CdSe/ZnS quantum dots : opportunities in luminescence sensing

Sutter, Jens U. and Birch, David J. S. and Rolinski, Olaf J. (2011) The effect of intensity of excitation on CdSe/ZnS quantum dots : opportunities in luminescence sensing. Applied Physics Letters, 98 (2). ISSN 0003-6951

Full text not available in this repository. (Request a copy from the Strathclyde author)

Abstract

We report changes in the photophysical properties of core-shell type CdSe/ZnS quantum dots (QDs) under optical irradiation. QDs either in aqueous solution or immobilized in a silica sol gel matrix have been excited at different wavelengths and fluxes. Illumination of the sample with 140 fs 700 nm Ti:sapphire laser pulses of the peak power of the order of 4 GW/cm(2) caused gradual increase in the luminescence lifetime from an initial value of 3.5 increasing to 4.5 ns and an increase in luminescence intensity by similar to 8%. Using about 16 GW/cm(2) peak power resulted in a shortening of the luminescence lifetime to 3 ns and a decrease in intensity by similar to 75%. Both photobrightening and photodarkening were fully reversible. We discuss the kinetics of photobrightening and photodarkening and investigate the suitability of QDs as luminescence lifetime sensors with tunable parameters.